* Added Max Instances property to Blocks
* eslint cleanup
* eslint cleanup 2
* Moved maxInstances property from block to workspace (as a map of block type to max instances). isDuplicate() changed to correctly handle siblings/branches.
* eslint cleanup
* Changed checking types to map. Added hasBlockLimits. Fixed Nits.
* Added limit_instances test block. eslint fixes.
* fixup! Added limit_instances test block. eslint fixes.
* Changed sorting objects to a private static function of the workspace. Fixed nits. Undeleted .eslintrc
* Reverted .gitignore file.
* Added getBlockTypeCounts() to utils. Added isCapacityAvailable() to workspace. Changed clipboard to save typeCountsMap rather than object.
Adds two new blocks to the playground's test blocks.
Fixes dropdown which previously could not be set to 'Test Blocks' due to missing condition.
Simplifies detection of file:// url.
Adds test blocks to demonstrate capabilities. Stopped short of adding BiDi override characters.
I added to the toolbox category "Images". It isn't really images, but it didn't seem worth making a separate category at this stage.
